Fluid operated well pumping apparatus



C. J. COBERLY FLUID OPERATED WELL PUMPING APPARATUS May 30, 1967 5 Sheets-Sheet 1 Filed Sept. 7, 1965 9,. w m, w WW M Z L a w Era. Z8 M P H a ra i 0 5M m .5

y 30, 1967 I c. J. COBERLY, 3,322,069

FLUID OPERATED WELL PUMPING APPARATUS Filed Sept. 7, 1965 s Sheets-Sheet 2 Hkmws, K m/g 19055644. WEQZJ May 30, 1967 C. J. COBERLY FLUID OFERATED WELL PUMPING APPARATUS Filed Sept. 7, 1965 5-Sheets-Sheet a May 30, 1967 c. J. COBERLY FLUID OPERATED WELL PUMPING APPARATUS 5 Sheets-Sheet 5 Filed Sept. 7, 1965 e 5 5 0 l a A w I 7 1 1 W M t ii? i m 1 0 0 0 H I 0,. w u M'WWLI W 6 ,i 1 ii\ & v[ 1!! a W I 1 1: -11; n M E Z v C W 0.x 4 w v E r d M j M p. z E 1 W R fl United States Patent 3,322 069 FLUID OPERATED WELL PUMPING APPARATUS Clarence J. Coberly, San Marino, Califi, assignor to Kobe,

inc, Huntington Park, Calif., a corporation of Caliornia Filed Sept. 7, 1965, Ser. No. 485,345 21 Claims. (Cl. 10346) The present invention relates in general to a fluid operated pumping apparatus for wells, particularly oil wells, and, more specifically, to a pumping apparatus of the socalled free type capable of being moved hydraulically through a tubing system between a bottom-hole operating position in a well and a surface control station at which the apparatus can be inserted into or removed from the tubing system.

One primary object of the invention is to provide a pumping apparatus of the foregoing nature which consists of or includes a high-capacity fluid operated pump short enough to negotiate short-radius bends in the tubing sys tern, i.e., bends having radii of the order of a few feet.

Another primary object is to provide a pumping apparatus of the foregoing general nature which is made up of articulately interconnected units short enough to negotiate short-radius bends in the tubing system, and wherein at least one of the articulately interconnected units comprises a fluid operated pump of the character outlined in the preceding paragraph.

A more specific object is to provide a pumping apparatus comprising articulately connected units wherein at least one of the units includes fluid operated engine means and pump means connected to and operable by the engine means, and wherein another of the units includes packer means engageable with the interior of the tubing system to provide a substantially fluid tight seal between the pumping apparatus and the tubing system irrespective of the direction of hydraulically induced movement of the pumping apparatus through the tubing system. A related object is to provide such a pumping apparatus which includes: an uppermost, one or more intermediate, and a lowermost elongate unit; means articulately interconnecting these units in end-to-end relation; the uppermost unit including a packer mandrel carrying oppositely facing packer cups engageable with the interior of the tubing system; each of the intermediate units comprising a fluid operated pump having fluid operated engine means and pump means connected to and operable by the engine means; and the lowermost unit including fluid operated booster pump means for delivering the fluid to be pumped to the intermediate units under pressure and in parallel.

The invention contemplates an axially-short, high-capacity, fluid operated pump suitable for use in the foregoing manner, or for independent use, which is of the rotary, axial-plunger type. More particularly, the invention contemplates a fluid operated pump comprising a rotor rotatable about the axis of the pump and provided with circumferentially spaced, fluid operated, pumping devices reciprocable relative to the rotor along axes parallelling the rotor axis, each of the pumping devices including fluid operated engine means and pump means connected to and operable by the engine means. Still more specifically, the invention contemplates a rotary fluid operated pump of this character wherein the fluid operated pumping devices comprise axially reciprocable, combined engine and pump plunger means coacting with cam means carried by the pump housing to rotate the rotor about its axis in response to reciprocatory movement of the plunger means, the pump further. including engine valve means responsive to rotation of the rotor for sequentially connecting the engine means of the pumping devices to an operating fluid intake and exhaust alternately, and pump valve means also re- 3,322,059 Patented May 30, 1967 sponsive to rotation of the rotor for sequentially connecting the pump means of the pumping devices to a production fluid inlet and outlet alternately.

A rotary fluid operated pump of the foregoing general nature is disclosed in my Patent No. 2,625,109, granted January 13, 1953. A pump of this type in addition to being axially short and having a high capacity, also minimizes hydraulic shock in the operating-fluid and/ or productionfluid tubings of the system because of its multiple-plunger construction. Consequently, such a pump requires no auxiliary means for reducing hydraulic shock effects.

A further primary object of the present invention is to provide a rotary fluid pump of the foregoing general character which incorporates various very important improvements on the pump of the aforementioned patent.

An important object of the invention is to provide such a rotary fluid operated pump wherein the fluid operated pumping devices respectively include fluid operated engine means and pump means which are spaced apart axially of the rotor. More particularly, an important object is to provide fluid operated pumping devices respectively comprising cylinder means having axially spaced engine and pump cylinders, and respectively comprising plunger means having axially spaced, interconnected engine and pump pistons respectively reciprocable axially of the engine and pump pistons respectively reciprocable axially 'of the engine and pump cylinders.

The rotary fluid operated pump of my aforementioned patent comprises pumping devices respectively having concentrically-arranged engine and pump means and having pump means which are single acting. The present invention, by locating the engine means and the pump means of each pumping device in axial alignment in end-to-end relation, achieves a capacity more than double that of the concentric arrangement of my prior patent, the reasons being that larger engine and pump pistons, and larger operating-fluid and production-fluid passages, are possible. Such larger passages increase the capacity of the pump by enabling the rotor to rotate at a much higher speed. Another object in this general connection is to make the pumping devices differential double acting, which reduces any pressure pulsations by a factor of two.

Another important object of the invention is to provide cylindrical cam means coaxial with and encircling the rotor and responsive to reciprocatory movement of the plunger means for rotating the rotor about its axis.

Another object of the invention is to provide such a cylindrical cam means which includes a double-acting cam and roller cam followers respectively carried by the plunger means and engaging the cam. With this construction, the cam can be utilized to constrain the motion of the plunger means to any desired pattern, an object in this connection being to provide a cam which causes the plunger means to dwell at the ends of their strokes as the engine valve means sequentially connects the engine means to and disconnects them from the intake and the exhaust alternately, and which then controls the acceleration of the plunger means during the initial portions of their strokes, subsequently permits the plunger means to move at uniform velocities through the major portions of their strokes, and finally controls the deceleration of the plunger means during the terminal portions of their strokes. Since the cam is double acting, the motions of the plunger means can be different during their intake and discharge strokes, which is an important feature.

Another object of the invention is to provide a rotary fluid operated pump wherein the operating-fluid intake and exhaust passages and the production-fluid inlet and outlet passages have the same areas as the engine and pump pistons to permit high speed operation of the rotor.

Additional objects of the invention are to provide a rotary fluid operated pump of the foregoing nature wherein each of the engine pistons has oppositely facing, major and minor engine areas, wherein each of the pump pistons has oppositely facing, major and minor pump areas, wherein the major engine and pump areas face oppositely, wherein passage means constantly connect the minor engine areas to the operating-fluid intake, wherein the engine valve means alternately connects the major engine areas to the operating-fluid intake and exhaust, wherein passage means constantly connect the minor pump areas to the production-fluid inlet, and wherein the pump valve means alternately connects the major pump areas to the production-fluid inlet and outlets. Related objects are to provide major engine and pump areas respectively equal to twice the minor engine and pump areas.

A further important object of the invention is to provide a rotary fluid operated pump as outlined above having passage means communicating with the operatingfluid intake for conducting clean operating fluid under pressure into the interfaces between all relatively movable components of the pump which are exposed to the production fluid being pumped. With this construction, the clean operating fluid constantly leaks through such interfaces at slow rates to lubricate the relatively movable surfaces and to preclude their contamination by the potentially-dirty production fluid so as to minimize wear, which is an important feature.

Another object of the invention is to so balance the hydraulic forces on the rotor as to give the desired con-' tact pressures between the ends of the rotor and engine and pump valve members in engagement with the respective ends of the rotor, such engine and pump valve members constituting parts of the engine and pump valve means hereinbefore mentioned.

The foregoing objects, advantages, features and results of the present invention, together with various other objects, advantages, features and results thereof which will be evident to those skilled in the fluid operated pump art in the light of this disclosure, may be achieved with the exemplary embodiment of the invention described in detail hereinafter and illustrated in the accompanying drawings, in which:

FIG. 1 is a semidiagrammatic view fragmentarily illustrating an offshore well completion with which the fluid operated well pumping apparatus of the invention may be used;

FIG. 2 is a vertical sectional view of the lower or bottom-hole end of a well tubing system installed in the oil well of FIG. 1 and capable of receiving the fluid operated well pumping apparatus of the invention therein, FIG. 2 being taken as indicated by the irregular arrowed line 2-2 of FIG. 8, which will be described hereinafter;

FIG. 3 is a downward continuation of FIG. 2;

FIG. 4 is a downward continuation of FIG. 3;

FIG. 5 is a downward continuation of FIG. 4;

FIG. 6 is a downward continuation of FIG. 5;

FIG. 7 is a downward continuation of FIG. 6 and shows the lowermost portions of the bottom-hole end of the well tubing system;

FIGS. 8 and 9 are transverse, horizontal sectional views respectively taken along the arrowed lines 8-8 and 9-9 of FIGS. 2 and 3;

FIGS. 10, 11 and 12 are fragmentary transverse, horizontal sectional views respectively taken along the arrowed lines 1010, 1111 and 12-12 of FIG. 5;

FIG. 13 is an enlarged developed view of a cylindrical, double-acting cam incorporated in the fluid operated well pumping apparatus of the invention;

FIGS. 14 and 15 are fragmentary transverse, horizontal sectional views respectively taken along the arrowed lines 1414 and 15-15 of FIG. 5; and

FIG. 16 is an enlarged, fragmentary, horizontal sectional view taken as indicated by the arrowed line 1616 of FIG. 6.

4 GENERAL DESCRIPTION Referring initially to FIG. 1 of the drawings, the numeral 20 designates an offshore oil well completion with which a free-type, fluid operated pumping apparatus 22, FIGS. 2 to 7, of the invention may be used. The well completion 20 comprises a well bore 24 drilled into the ocean floor 26 at an ofishore location. The well C0111". pletion 20 is intended to be produced from a suitable pumping station, not shown, which may be an onshore station, an island, a stationary or floating offshore platform, or the like.

The well completion 20 is shown as including an outer, surface casing 28 set in the upper end of the well bore 24 and an inner casing 30 disposed within the outer casing and extending downwardly into the well bore below the lower end of the outer casing. Production fluid from an oil-producing formation or formations surrounding the well bore 24 may enter the inner casing 30 in various ways. For example, the producing zone or zones may be left uncased, where the formation or formations are sufficiently consolidated to permit this, in which event the production fluid enters the inner casing 30 through its lower end. Alternatively, production fluid may enter the inner casing through perforations therein, not shown, through a perforated liner, not shown, connected to the inner casing, or the like.

Surmounting and connected to the upper end of the outer casing 28 is a suitable well head 32. The inner casing 30 is suspended from and sealed relative to the well head 32 in any suitable manner, as disclosed, for example, in co-pending application Ser. No. 276,820, filed Apr. 30, 1963 by Clarence J. Coberly, Jr., Russell G. Ralph and Clarence J. Coberly. Disposed in the inner casing 30 is a tubing assembly 34, FIGS. 2 to 7, suitably suspended from the well head 32, as disclosed, for example, in the co-pending application mentioned.

Referring to FIGS. 2 to 7 of the drawings, in the particular construction illustrated, the tubing assembly 34 constitutes a closed system composed of three tubings 36, 38 and 40. The tubing 36 is of a size to slidably receive the free, fluid operated pumping apparatus 22 for movement therethrough between the well head 32 and an operating position in a bottom hole assembly 42, FIGS. 3 to 7, comprising the lower end of the tubing assembly 34. In view of this function of the tubing 36, it will be referred to hereinafter as a pump tubing. Preferably, but not necessarily, the pump tubing 36 also serves as a production tubing for conveying production fluid discharged by the pumping apparatus 22, when it is in its operating position in the well 20, upwardly to the well head 32.

In the construction illustrated, the tubings 36, 38 and 40 are parallel tubings, i.e., they are located in side-byside relation. The parallel tubing 38 is a supply tubing for conveying operating fluid under pressure downwardly in the well 20 to the pumping apparatus 22, when it is in its operating position, to operate same. The spent operating fluid is returned to the well head 32 through the parallel tubing 40. It will be understood that the free, fluid operated pumping apparatus 22, which will be described in detail hereinafter, is intended to be circulated hydraulically between its operating position in the bottom hole assembly 42 and the well head 32.

The upper end of the pump tubing 36 registers with an adjacent end of a conductor tubing 44 of a size to permit hydraulically-induced sliding passage of the pumping apparatus 22 therethrough between the well head 32 and the aforementioned pumping station. As will be described hereinafter, the construction of the pumping apparatus 22 is such that it is capable of negotiating shortradius bends 46 and 48 in the conductor tubing 44, which is an important feature of the invention. For example, the bends 46 and 48 in the conductor tubing 44 may have radii of but a few feet.

Also connected to the well head 32 are supply and return lines 50 and 52 which communicate with the upper ends of the supply and return tubings 38 and 40, respectively, in the manner disclosed in the aforementioned co-pending application Ser. No. 276,820. The supply and return lines 50 and 52 lead to the well head from the remote pumping station mentioned.

The conductor tubing 44, including the bends 46 and 48 therein, is preferably a steel tubing. However, the conductor tubing 44 may include at the well head 32 a flexible terminal portion 54 having a lower end which is shiftable laterally from a position in register with the pump tubing 36 in the well to a position out of alignment with the well tubing assembly 34. As disclosed in detail in the aforementioned co-pending application Ser. No. 276,820, this permits servicing of the well 20 through a standpipe 56 mounted on the well head 32. The latter is provided with a shut-off valve 58 controlled from the pumping station through a hydraulic line 60, and is provided with a latch unit 62 also controlled from the pumping station through a hydraulic line 64. The latch unit 62 is capable of securing the lower end of a conductor pipe, not shown, lowered into the standpipe 56 from a barge, or the like, through a guide funnel 66 at the upper end of the standpipe. The guide funnel has cables 68 connected thereto to which a marker buoy, not shown, may be attached to mark the location of the well completion 20. With the foregoing construction, which is disclosed in more detail in said co-pending application Ser. No. 276,820, the well completion 20 may be serviced, from a barge, or the like, through the conductor pipe latched in the standpipe 56.

The previously-mentioned lateral shifting of the terminal portion 54 of the conductor tubing 44 may be accomplished by an actuating unit 70 controlled from the pumping station through hydraulic lines 72 and 74 in the manner disclosed in said co-pending application Ser. No. 276,820. As also described in such co-pending application, the flexible terminal portion 54 of the conductor tubing 44 is contained in a housing 76 which may contain operating fluid under suificient pressure to nearly equalize the internal and external pressures acting on the flexable terminal portion 54, thereby minimizing the pressure differential across the wall of such portion.

Free fluid operated well pumping apparatus 22 generally Considering the fluid operated Well pumping apparatus 22 in a general way, it is hydraulically movable through the tubing system comprising the pump tubing 36 in the well and the conductor tubing 44, including any bends in the conductor tubing, such as the bends 46 and 48 shown. More particularly, the pumping apparatus 22 is made up of articulately interconnected units short enough to negotiate short-radius bends in the tubing system through which the apparatus is intended to be circulated hydraulically at least one of such articulating interconnected units comprising a high-capacity fluid operated pump.

In the particular construction illustrated, the pumping apparatus 22 consists of four articulately interconnected units 82, 84, 86 and 88. It will be understood, however, that the invention is not limited to any specific number of articulately interconnected units, except insofar as may be required by the claims appended hereto.

Considering the articulated pumping apparatus 22 in its operative position, shown in FIGS. 2 to 7 of the drawings, the uppermost unit 82 is a packer unit on which operating fluid under pressure'acts to circulate the apparatus hydraulically, through the pump tubing 36 in the well and the conductor tubing 44, between its operating position in the well and the remote pumping station. More particularly, the packer unit 82 comprises the usual packer mandrel 90 shown as having thereon two downwardly facing packer cups 92 and at least one upwardly facing packer cup 94. The packer mandrel is provided at its upper end with the usual tapered nose 96 for engagement by a conventional pump catcher, not shown, at the remote pumping station.

When the articulated pumping apparatus 22 is in its operating position, the packer cups 92 and 94 are disposed in a packer barrel 98 constituting part of the bottom hole assembly 42 and connected to the lower end of the pump tubing 36. When the articulated pumping apparatus 22 is in its operating position, the downwardly facing packer cups 92 are disposed in internal annular recesses 100 in the packer barrel 98, the upwardly facing packer cup 94 being disposed in a similar recess 102. The recesses 100 and 102 provide annular clearances around the packer cups 92 and 94, respectively, when the pumping apparatus 22 is in its operating position, so that production fluid discharged by the apparatus, in a manner to be described hereinafter, can flow upwardly through the packer barrel 98, and past the packer cups 92 and 94, into the pump tubing 36, and from the latter into a production line 104, FIG. 1, leading to the remote pumping station. When the pumping apparatus 22 is moved upwardly out or" its operating position slightly in a manner to be described, the downwardly facing packer cups 92 clear the recesses 100 so that operating fluid under pressure introduced beneath the pumping apparatus circulates upwardly through the pump tubing 36 to the well head 32 and then through the conductor tubing 44 to the remote pumping station. Hydraulic circulation of the pumping apparatus 22 in the opposite direction is achieved by introducing operating fluid under pressure into the conductor tubing 44 at the pumping station, such operating fluid acting on the upwardly facing packer cup 94 to circulate the pumping apparatus through the conductor tubing 44 and then downwardly through the pump tubing 36 into its operating position.

The units 84 and 86 are fluid operated, rotary, axialplunger pump units which will be described in more detail hereinafter. Considering the pump units 84 and 86 generally for the time being, they include fluid operated engine means connected in parallel between the supply tubing 38 and the turn tubing 40 so that they operate independently of each other. The engine means of the pump units 84 and 86 operate pump means thereof which are also connected in parallel between a well fluid inlet to be described and the production or pump tubing 36, so that the pump means of the two pump units also operate independently of each other. Thus, the two pump units are hydraulically connected in parallel in all respects to provide a combined production-fluid output equal to the sum of the respective production-fluid outputs thereof.

The lowermost unit 88 comprises a fluid-operated booster pump for delivering Well fluid at increased pressure to the production fluid inlets of the pumps 84 and 86. The booster pump 88 has an engine means hydraulically connected in parallel with the engine means of the pumps 84 and 86, and has a pump means hydraulically connected in series with the pump means of the pumps 84 and 86.

Referring to FIG. 7 of the drawings, at the lower end of the articulated pumping apparatus 22, and connected to the lower end of the booster pump 88, is an inlet fitting 106 for production fluid from the well 20, such inlet fitting having an inlet passage 108 which communicates with a production fluid inlet 110 of the booster pump 88. The lower end of the inlet fitting 106 is tapered and is seated on a complementary seat 112 at the upper end of a stand ing valve assembly 114 which communicates at its lower end with the well 20 in the usual manner. The standing Valve assembly 114 is carried by an annular seat 116 therefor adjacent the lower end of the bottom hole assembly 42.

The four units 82, 84, 86 and 88 of the pumping apparatus 22 are articulately interconnected by ball-andsocket joints 122, 124 and 126, the joint 122 interconnect- '84 and 86, and the joint 126 interconnecting the lower pump 86 and the booster pump 88.

'The ball-and-socket joint 122 includes a ball 128 connected to the lower end of the packer unit 82 and secured in a socket in the upper end of the upper pump 84 by a gland 130. Similarly, the ball-and-socket joint 124 includes a ball 132 connected to the lower end of the upper pump 84 and secured in a socket in the upper end of the lower pump 86 by a gland 134. Again, similarly, the ball-and-socket joint 126 includes a ball 136 connected to the lower end of the lower pump 86 and secured in a socket in the upper end of the booster pump 88 by a gland 138.

With the foregoing construction, the articulated pumping apparatus 22 is capable of bending to permit it to negotiate bends in the tubing system through which it is hydraulically circulated, such as the bends 46 and 48 in the conductor tubing 44. The various units 82, 84, 86 and 88 are sufliciently short that the articulated pumping apparatus 22 is capable of negotiating bends having radii of as little as a few feet.

The minimum bend radius, R, which can be negotiated by a cylindrical body of constant diameter through its length, I can be determined from the equation where h is the difference between the diameter of the cylindrical body and the inside diameter of the conductor tubing 44. Utilizing values of one inch and 18 inches for h and 1, respectively, R is less than three and one-half feet. A value of l of 18 inches for the pump units 84, 86 and 88 provides adequate pumping capacities, and the packer unit 82 can readily accommodate a value of one inch for h. Further, since, as will be noted from the drawings, the pump units 84, 86 and 88 have reduced diameters at their ends, whereas the equation given is for a constant-diameter cylindrical body, R can be further reduced for the same values of h and l, or h can be decreased for the same values of R and 1.

Running articulated pumping apparatus 22 in and out of the well 20 In order to run the articulated pumping apparatus 22 7 into the well 20, the apparatus is first inserted into the conductor tubing 44 at the remote pumping station, not

shown. Then, operating fluid is introduced into the conductor tubing 44 above, i.e., outwardly of, the articulated pumping apparatus 22. Such operating fluid acts on the upwardly facing packed cup 94 to displace the pumping apparatus through the conductor tubing 44 and then downwardly through the pump tubing 36, the fluid pressure applied to the pumping apparatus being suflicient only to produce the desired movement thereof. Ultimately, the articulated pumping apparatus 22 reaches its operating position in the well 20, at which time the inlet fitting 106 at the lower end of the apparatus is seated on the standing valve assembly 114.

As the articulated pumping apparatus 22 is being run in in the foregoing manner, the fluid in the conductor tubing 44 and the pump tubing 36 below or inwardly of .the apparatus is displaced upwardly or outwardly to the pumping station through the return tubing 40 and the return line 52. Preferably, the supply line 50 is closed at the pumping station to prevent displacement of possibly-dirty fluid into the supply tubing 38 and the supply line. Consequently, when the pumping apparatus 22 is subsequently placed in operation, contamination of the apparatus by such possibly-dirty fluid is prevented.

Considering the manner in which the fluid in the pump tubing 36 is displaced into the return tubing 40, the bottom hole assembly 42 is provided, as shown in FIG. 7, with passage means 142 communicating with the interior a 8 of the bottom hole assembly at a level just above the standing valve assembly 114. The bottom hole assembly 42 includes a parallel return passage 144 which communicates V at its lower end with the passage means 142, and which extends upwardly into communication with the lower end of the return tubing 40, as shown in FIG. 3. Thus, as the articulated pumping apparatus 22 is run in, fluid in the pump tubing 36 therebelow is displaced through the passage means 142 into the return passage 144. From the latter, the displaced fluid flows through the return tubing 40 and the return line 52 to the remote pumping station.

In order to run the articulated pumping apparatus 22 out, operating fluid under pressure suflicient for the purpose is introduced into the return line 52 at the remote pumping station, the production line 104 being open at the pumping station. The supply line 50 is preferably closed at the pumping station, again'to prevent contamination of the supply tubing 38 and the supply line 50 with possibly-dirty fluid. The pressure of the operating fluid introduced into the return line 52 at the pumping station is transmitted to an annular area at the lower end of the inlet fitting 106 of the pumping apparatus 22 through the return line 52, the return tubing 40', the return passage 144 and the passage means 142. Initially, the. operating fluid pressure displaces the pumping apparatus 22 upwardly until the downwardly-facing packer cups 92 are displaced upwardly above their recesses in the packer barrel 98. During this initial upward movement of the pumping apparatus 22, bypassing of the operating fluid upwardly past the pumping apparatus is prevented by engagement of various external annular seals thereon with the interior of the bottom hole assembly 42. Subsequently, the operating fluid under pressure introduced below the. pumping apparatus 22 acts on the downwardly-facing packer cups 92 to circulate the apparatus upwardly through the pump tubing 36 to the well head 32, and then outwardly through the conductor tubing 44 to the remote pumping station. As will be apparent, the fluid in the pump tubing 36 and the conductor tubing 44 above or outwardly of the pumping apparatus 22 is displaced through the pump tubing and the conductor tubing to the remote pumping station.

Operating fluid supply system Referring to FIG. 3 of the drawings, the lower end of the supply tubing 38 communicates through a passage means 146 with an annular clearance 148 around the balland-socket joint 122 interconnecting the packer unit 82 and the upper pump 84, such annular clearance being formed between the ball-and-socket joint 122 and the bottom hole assembly 42 and being sealed at its upper and lower ends by suitable external annular seals on the packer unit and the upper pump. Operating fluid under pressure reaching the annular clearance 148 in the foregoing manner flows through radial passage means 150 in the balland-socket joint 122 into an axial passage 152 in the body 7 of the upper pump 84. As shown in FIG. 4, the axial paspump 84 and the'bottom hole assembly 42, such annular passage being sealed at its upper and lower ends by suitable external annular seals carried by the upper pump and engaging the bottom hole assembly. The annular passage 158 communicates at its lower end with a longitudinal passage 160, FIG. 4, in the lower end of the body of the upper pump 84. The passage 160 conveys operating fluid under pressure downwardly to an annular clearance 162 around the ball-and-socket joint 124 interconnecting the. upper and lower pumps 84 and 86-, such annular clearance also being sealed at its upper and lower ends by external annular seals on the upper and lower pumps and engaging the bottom hole assembly 42. From the annular clearance 162, operating fluid under pressure flows through radial passage means 164 in the ball-and-socket joint 124 into an axial passage 166 in the upper end of the body of the lower pump 86. As shown in FIG. 5, the axial passage 166 communicates at its lower end with an operating fluid intake 168 of the lower pump 86.

Adverting to FIG. 4, the body of the lower pump 86 is provided therein with a radial port 170 for conveying operating fluid under pressure from the axial passage 166 to an annular passage 172 around the lower pump, such annular passage being sealed at its upper and lower ends by external annular seals on the lower pump and engaging the bottom hole assembly 42. Turning to FIG. 6 of the drawings, the annular passage 172 communicates at its lower end with a longitudinal passage 174 in the lower end of the body of the lower pump 86. The passage 174 conveys operating fluid under pressure downwardly to an annular clearance 176 around the ball-and-socket joint 126 interconnecting the lower pump 86 and the booster pump 88. The annular clearance 176 is sealed at its upper and lower ends by suitable external annular sealscarried by the lower and booster pumps 86 and 88 and engaging the bottom hole assembly 42. The annular clearance 176, which also extends downwardly around and surrounds the booster pump 88, communicates with a radial port 178 in the upper end of the body of the booster pump. The radial port 178 communicates at its inner end with the upper end of a longitudinal port 180 for conveying operating fluid under pressure downwardly to an operating fluid intake 182 of the booster pump 88.

Spent operating fluid return system Considering the spent operating fluid return system associated with the articulated pumping apparatus 22 when in its operating position, and starting at the lower end of the apparatus for convenience, the booster pump 88 includes an operating fluid exhaust 184, FIG. 7, which communicates with a longitudinal passage 186 in the inlet fitting 106. The passage 186 communicates at its lower end with an annular clearance 188 around the inlet fitting 106, such annular clearance being sealed at its upper end by an external annular seal carried by the inlet fitting and engaging the bottom hole assembly 42, and being sealed ats its lower end by engagement of the standing valve assembly 114 with its annular seat 116. The annular clearance 188 communicates with the passage means 142 leading to the return passage 144. Consequently, spent operating fluid discharged by the booster pump 88 is conveyed to the return passage 144 through the longitudinal passage 186, the annular clearance 188 and the passage means 142.

Referring to the upper end of FIG. 5, the lower pump 86 is provided with an operating fluid exhaust 190 communicating with the lower end of a longitudinal passage 192 in the upper end of the body of the lower pump. Referring to the lower end of FIG. 4, the passage 192 communicates with a passage means 194 for conveying spent operating fluid to the return passage 144.

Referring to the upper end of FIG. 4, the upper pump 84 is provided with an exhaust 196 for spent operating fluid which communicates with a longitudinal passage 198 in the upper end of the body of the upper pump 84. The passage 198, as shown in FIG. 3, communicates with a passage means 200 for conveying spent operating fluid from the passage 198 to the return passage 144.

Thus, the upper, lower and booster pumps 84, 86 and 88 all discharge spent operating fluid into the return passage 144. From the return passage 144, the spent operating fluid flows to the remote pumping station through the return tubing 40 and the return line 52.

Production fluid inlet system Referring to FIG. 7 of the drawings, production fluid from the well enters the production fluid inlet 110 of the booster pump 88 through the standing valve assembly 114 and the axial inlet passage 108 in the inlet fitting 106. The booster pump 88 discharges the production fluid at an elevated pressure into an annular passage 204, FIG. 6, within the booster pump adjacent the upper end thereof. The annular production fluid passage 204 communicates at its upper end with a radial port 206 leading to an axial passage 208 in the upper end of the body of the booster pump. The axial passage 208 communicates at its upper end with an axial passage 210 through the lower balland-socket joint 126. The upper end of the axial passage 210 communicates with the lower end of an axial passage 212, FIGS. 5 and 6, in the lower end of the body of the lower pump 86. The passage 212 conveys production fluid at the boosted pressure to a production fluid inlet 214 of the lower pump 86.

Adverting to FIG. 6, the axial passage 212 communicatse with a radial port 216 which, in turn, communicates with a radial passage means 218 in the bottom hole assembly 42. The radial passage means 218 communicates withradial ports 220 in a spider 222, FIGS. 6 and 16, within the return passage 144. concentrically disposed in the return passage 144 is a production fluid inlet tube 224 the lower end of which is connected to the spider 222 in fluid communication with the radial ports 220 therein. The upper end of the production fluid inlet tube 224 is connected to an upper spider 226, FIG. 4, in communication with radial ports 228 there-in. It will be noted that the production fluid inlet tube 224 is spaced inwardly from the wall of the return passage 144 so that spent operating fluid can flow upwardly through the lower spider 222, the annular clearance around the tube 224, and the upper spider 226.

The radial ports 228 in the upper spider 226 communicate with a radial passage means 230 which, in turn, communicates with a radial port 232 in the lower end of the body of the upper pump 84. The radial port 232 conveys boosted production fluid inwardly to an axial passage 234 in the lower end of the body of the upper pump 84. The axial passage 234 communicates at its upper end with a production fluid inlet 236 of the upper pump 84.

As will be apparent from the foregoing, the production fluid inlets 214 and 236 of the lower and upper pumps 86 and 84 are connected in series with the production fluid outlet of the booster pump 88, but are connected in parallel with respect to each other. Thus, the upper and lower pumps 84 and '86 operate independently of each other.

Production fluid outlet system.

Refening to the lower end of FIG. 5 and the upper end of FIG. 6, the lower pump 86 is provided with a production fluid outlet 240 which communicates with the upper end of a longitudinal passage 242 in the lower end of the body of the lower pump. The longitudinal passage 242 communicates at its lower end with a radial port 244, FIG. 6, which, in turn, communicates with a radial passage fiesans 246 leading to a parallel production fluid passage The production fluid passage 248 extends upwardly to a point adjacent the upper end of the bottom hole assembly 42, as shown in FIGS. 3, 4, 5 and 6. As shown in FIG. 4, the upper pump 84 is provided with a production fluid outlet 250 communicating with the upper end of a longitudinal passage 252 in the lower end of the body of the upper pump. The passage 252 communicates at its lower end with a radial port 254 which, in turn, communicates with radial passage means 256 in the bottom hole assembly 42. The radial passage means 256 communicates with the production fluid passage 248.

Turning to FIG. 3 of the drawings, the production fluid passage 248 communicates at its upper end with radial passage means 258 communicating, in turn, with the lower ends of longitudinal passages 260, FIGS. 3 and 9, in the bottom hole assembly 42. The longitudinal passages 260 communicate at their upper ends with the 11 lower end of the packer barrel 98 so that the production fluid discharged by the upper and lower pumps 84 and 86 can flow upwardly through the packer barrel, and around the packer cups 92 and 94 therein, into the production tubing 36, and thence into the production line 104 leading to the remote pumping station.

Pumps 84 and 86 generally As will be apparent from the foregoing discussions of the operating fluid supply system, the spent operating fluid return system, the production fluid inlet system and the production fluid outlet system, the two fluid operated pumps 84 and 86 are connected in parallel both between the supply tubing 38 and the return tubing 48 and between the production fluid outlet of the booster pump 88 and the production tubing 36. Consequently, the two pumps 84 and 86 operate independently of each other and have a combined production-fluid output equal to the sum of the respective production-fluid outputs thereof.

In accordance with the primary objects of the invention, the fluid operated pumps 84 and 86 are axiallyshort units to enable them to negotiate short-radii bends in the tubing system through which the articulated pumping apparatus 22 is to be circulated. Further, the fluid operated pumps 84 and 86 have high production-fluid outputs relative to their axially-short lengths, and minimize hydraulic shock in the operating-fluid and/ or productionfluid components of the over-all installation.

The foregoing results are achieved by utilizing rotary, axial-plunger, fluid operated pumps 84 and 86 respectively comprising rotors rotatable about the axes of the pumps and provided with circumferentially spaced, fluid operated, pumping devices reciprocable relative to the rotors along axes paralleling the rotor axes, each of the pumping device-s including fluid operated engine means and pump means connected to and operable by the engine means. More particularly, the fluid operated pumps 84 and 86 comprise axially-reciprocable, combined engine and pump plunger means coacting with cam means carried by the pump bodies or their axes in response to reciprocatory movement of the plunger means, the pumps 84 and 86 further including engine valve means responsive to rotation of the rotors for sequentially connecting the engine means of the pumping devices to the hereinbefore-described respective operating fluid intakes and exhausts alternately, and still further including pump valve means also responsive to rotation of the rotors for sequentially connecting the pump means of the pumping devices to the hereinbeforedescribed respective production fluid inletsand outlets alternately.

Bothof the fluid operated pumps 84 and 8*? have the foregoing general construction and are preferably identical. Consequently, only the pump 86 will be considered in detail herein.

Fluid operated, rotary, axial-plunger pump 86 "As best shown in FIG. of the drawings, the pump 86 includes a body or housing 206 connected to the pump 84 by the ball-and-socket joint 124 and connected to the booster pump 88 by the 'ball-and-socket joint 125. The pump. housing 266 is provided therein with a cylindrical rotor chamber 268 having an upper or engine end wall 270 and a lower or pump end wall 272.

More particularly, the rotor chamber 268 is defined by a cylindrical barrel 274 having threaded into the upper end thereof a fitting 276 which defines the engine end wall 270 of the rotor chamber, which has the operating fluid intake and exhaust 168 and 190 formed therein, and which constitutes part of an engine valve means of the pump 86.

Slidably and rotatably disposed in the lower end of the barrel 274 is an insert 27 8 which defines the pump end wall 272 of the rotor chamber 268, which has the production fluid inlet and outlet 214 and 240 formed therein, and

housings to rotate the rotors about which constitutes part of a pump valve means of the pump 86. The insert 278 may be rotated within the 'barrel 274 to properly locate the production fluid inlet and outlet 214 and 240 circumferentially, and may be displaced axially of the barrel into its proper axial position. The

insert 278 is retained in its proper axial position by a lower fitting 280 threaded into the lower end of the barrel insert 278 by upper and lower set screws 284 and 286,

FIGS. 10 and 15, respectively. With this construction,

the lower insert 278 is held in its proper circumferential position.

The spindle 282 is provided with upper and lower spindle portions'288 and 290 for a purpose to be explained in the next paragraph. The spindle 282 includes, intermediate the upper and lower spindle portions 288 and 290, a cylindrical cam or cam portion 292 which performs a function to be described hereinafter. 7

Disposed in the lower chamber 68 is a sectional rotor 300 comprising an upper, engine section 302 rotatable on the upper spindle portion 288 and a lower, pump section 304 rotatable on the lower spindle portion 290. Above and abutting the upper end of the pump section 304 is in intermediate rotor section 306 rotatable on an intermediate-diameter portion 308 of the spindle 282. The engine section 302 of the rotor is provided with an upper or engine end wall 310 rotatably slidable relative to the engine end wal 270 of the rotor chamber 268. Similarly, the pump section 304 is provided with a lower or pump end wall 312 rotatably slidable relative to the pump end wall 272 of the rotor chamber 68. As will be described hereinafter, the engine end walls 270 and 310 cooperate to provide an engine valve means and the pump end walls 272 and 312 cooperate to provide a pump valve means.

The rotor 300 carries circumferentially spaced,'fluid' rotor, the pumping devices including fluid operated engine means and pump means connected to and operableby the engine means. More particularly, the fluid operated pumping devices 314 comprise circumferentially spaced engine plungers or pistons 316 reciprocable in circumferentially spaced engine cylinders 318 in the engine rotor section 302, and comprise circumferentially spaced pump plungers or pistons 320 connected to the respective engine pistons and reciprocable in circumferentially spaced pump cylin ders 322 in the pump rotor section 304. The engine and pump cylinders 318 and 322 extend entirely through the respective engine and pump sections 302 and 304 of the rotor 300.

Considering the interconnections between the engine and pump pistons 316 and 320, each engine piston is provided at its lower end, and below the engine rotor section 302, with a portion 324, FIG. 12, of generally trapezoidal crosssection having a cylindrically'arcuate inner surface 326 journalled on the cylindrical cam portion 292 of the spindle 282. More particularly, the trapezoidal portions 324 are rotatable relative to the cam por tion 292 about the axis thereof, and are simultaneously reciprocable relative to such cam portion and to each other. Each pump piston 320 is provided with an upwardly extending, axial rod or stem 328 reciprocable in Positioned axially of the rotor chamber 268 is a spindle V As will be explained hereinafter, alternating fluid pressure force differentials are applied to the engine pistons 316 to cause them to reciprocate the corresponding pumping devices 314, whereupon the corresponding pump pistons 320 pump production fluid from the inlet 214 to the outlet 240. Such reciprocatory movement of the fluid operated pumping devices 314 is converted to rotary movement of the rotor 380 by a double-acting cylindrical cam means 332 coaxial with the rotor and located intermediate the ends thereof.

Considering the cam means 352, it includes a doubleacting cam groove 334 formed in the cylindrical cam portion 292 of the spindle 282. The cam groove 334 is of tapered, e.g., trapezoidal, cross section and receives tapered, e.g., trapezoidal, roller cam followers 336 therein. These cam followers have their larger ends seated against the trapezoidal portions 324 of the engine pistons 316, as best shown in FIG. 12, and are provided with spindles 338 extending radially outwardly and journalled in bearing bores 340 in the trapezoidal portions.

Referring to FIG. 13 of the drawings, which is a developed view of the cam groove 334, the cam groove has an over-all configuration which can best be described as generally sinusoidal. Consequently, as the engine pistons 316 are reciprocated by the hereinafter-described application of an alternating fluid pressure force differential thereto, the cam followers 336 follow the generally sinusoidal cam groove 334 to convert the reciprocatory movement of the engine pistons into rotary movement of the rotor 300 about the axis of the spindle 282.

Since the cam groove 334 is double acting, i.e., since it acts on the fluid operated pumping devices 314 in both directions, it constrains the reciprocatory motion of the pumping devices to a particular pattern, which pattern can be varied as desired by varying the over-all configuration of the cam groove. For example, in the preferred configuration illustrated, the cam groove 334 is provided with upper and lower dwells 342 and 344 respectively corresponding to the ends of the upward and downward strokes of the pumping devices 314. Thus, the engine and pump pistons 316 and 320 are caused to dwell at the ends of their strokes as the engine and pump valve means, engine and pump cylinders 318 and 322 to and disconnect them from the operating fluid intake and exhaust 168 and 190 and the production fluid inlet and outlet 214 and 240, respectively. Preferably the cam groove 334 is provided with portions 346 between the dwells 342 and 344 which permit the pumping devices 314 to move at uniform velocities through the major portions of their strokes. The cam groove 334 is so formed at the junctions of the portions 346 with the dwells 342 and 344 as to accelerate and decelerate the pumping devices 314 gradually during the initial and terminal portions of their strokes. Although the cam groove 334 is shown as symmetrical, it may be asymmetrical to provide the pumping devices 314 with different motions during the production-fluid intake and discharge strokes of the pump pistons 320.

Turning now to a consideration of the manner in which the engine pistons 316 are reciprocated by applying an alternating fluid pressure force differential thereto, each engine piston is provided at its upper end with an upwardly facing, major area 348 alternately exposed to the operating fluid pressure in the intake 168 and the spent operating fluid pressure in the exhaust 190 as the rotor 300 rotates. This alternate exposure is effected by the engine valve means to be described hereinafter. The major area 348 of each engine piston 316 is equal to the crosssectional area of its 'engine cylinder 318.

Each engine piston 316 is also provided with a downwardly facing, net minor area, suggested by the numeral 350, equal to the difference between its major area 348 and the cross-sectional area of the corresponding piston rod 328. Preferably, the ratio of the major area 348 to the minor area 350 is 2:1.

The minor areas 350 of the engine pistons 316 are constantly exposed to the operating fluid pressure in the operating fluid intake 168. To accomplish this, radial ports 352, FIGS. 5 and 10, extend outwardly from the axial operating fluid passage 166 into communication with an annular clearance 354 surrounding the rotor sections 382, 304 and 306. Thus, the space between the rotor sections 302 and 306 is filled with operating fluid under pressure, whereby the minor areas 350 of the engine pistons 316 are constantly exposed thereto.

With the foregoing construction, when the major areas are exposed to the operating fluid pressure in the intake 168, the engine pistons 316 move the pumping devices 314 downwardly. Conversely, when the major areas 348 are exposed to the spent operating fluid pressure in the exhaust 190, the engine pistons 316 move the pumping devices 314 upwardly. Concurrently, the cam followers 336 cooperate with the cam groove 334 to rotate the rotor 300.

Similarly, the pump pistons 320 are provided at their lower ends with downwardly facing, major areas 356 equal to the cross-sectional areas of the pump cylinders 322. The pump pistons 320 are provided at their upper ends with upwardly facing minor areas 358 equal to the difference between the cross-sectional area of the pump cylinders 322 and the cross-sectional area of the piston rods 328. Again, the ratio of the major areas 356 to the minor areas 358 is preferably 2:1.

The minor areas 358 of the pump pistons 320 are constantly expoesd to the production fluid pressure in the inlet 214. More particularly, the axial production fluid inlet passage 212 communicates with the lower end of an axial passage 360 in the lower spindle portion 290. The upper end of the axial passage 360 communicates with radial ports 362 c ommunicating at their outer ends with an annular recess 364 in the lower end of the intermediate rotor section 306. The annular recess 364 constantly communicates with the upper ends of the pump cylinders 322 so as to constantly apply the production fluid inlet pressure to the minor areas 358 of the pump pistons 320.

As the rotor 300 rotates, the pump valve means to be described hereinafter alternately connects the lower ends of the pump cylinders 322 to the production fluid inlet and outlet 214 and 240. The lower ends of the pump cylinders 322 communicate with the production fluid inlet 214 during the upward strokes of the pumping devices 314 so that the pump pistons 320 draw production fluid into the lower ends of the pump cylinders. Conversely, during the downward strokes of the pumping devices 314, the lower ends of the pump cylinders 322 communicate with the production fluid outlet 240 so that the pump pistons 320 expel the production fluid therebeneath into the production fluid outlet.

Considering now the aforementioned engine valve means, the operating fluid intake 168 in the fitting 276 at the upper end of the pump-housing barrel 274 includes an arcuate port 370, FIG. 11, having an angular extent of somewhat less than The arcuate port 370 communicates with the operating fluid ports 352 through short longitudinal passages 372 in the fitting 276. The upper ends of the engine cylinders 318 communicate with the arcuate intake port 370 sequentially as the rotor 300 rotates, thereby sequentially exposing the major areas 348 at the upper ends of the engine pistons 316 to the operating fluid pressure to produce the downward strokes of the pumping devices 314, under the control of the cam means 332.

Similarly, the spent operating fluid exhaust in the fitting 276 includes an arcuate exhaust port 374 of an angular extent of somewhat less than 180, the arcuate exhaust port 374 communicating with the lower ends of the longitudinal passages 192. During the upward strokes of the engine pistons 316, the upper ends of the engine cylinders 318 communicate with the'arcuate exhaust port 374 to permit the discharge of spent operating fluid from such engine cylinders.

Summarizing the operation of the engine valve means,

the downward or working strokes of the pumping devices 314 occur when the engine cylinders 318 are in 00111111111111 municate with the arcuate exhaust port 374, and from positions wherein they communicate with the arcuate exhaust port into positions wherein they communicate with the arcuate intake .port.

Turning to the pump valve means, the production fluid inlet and outlet 214 and 240 in the lower fitting 280 respectively comprise arcuate inlet and outlet orts 376 and 378 respectively axially aligned with the arcuate exhaust and intake ports 374 and 370 of the engine valve means. The arcuate inlet port 376 communicates'with the axial production fluid inlet passage 212 through an arcuate passage 380, FIG. 15, and the arcuate outlet port 378 communicates with the production fluid outlet passage 342 through short longitudinal passages 382, FIGS. '5 and 15.

As will be apparent, during the upward strokes of the pumping devices 314, the lower ends of the pump cylinders 322 communicate with the arcuate inlet port 376 so that the pump pistons 320 draw production fluid into the lower ends of the pump cylinders. During the downward strokes of the pumping devices 314, the lower ends of the pump cylinders 322 communicate with the arcuate outlet port 378 so that the pump pistons 320 discharge production fluid from the pump cylinders into the production fluid outlet 240. The dwells 342 and 344 of the cam groove 334 cause the pumping devices 314 to dwell as the pump cylinders 322 move from a position wherein 16 sages 380 and 382 are quite large to minimize 'flow resistance with respect to the production fluid.

Another advantage of the pump 86 is that the pumping devices 314 are diflerential double acting, as opposed to they communicate with the arcualte inlet port 376 into i a position wherein they communicate with the arcuate outlet port 378, and as they move from a position wherein they communicate with the arcuate outlet port into a position wherein they communicate with the arcuate inlet ort. p Considering various advantageous features of the hereinbeforedescribed construction of the pump 86, it will be noted that the engine means and the pump means of each fluid operated pumping device 314 are axially spaced in end-to-end relation, the engine means of each pumping device being regarded as comprising the corresponding engine piston 316 and engine cylinder 318, and the pump means thereof being regarded as comprising the corresponding pump piston 320 and pump cylinder 322. Consequently, each pumping device 314 has a capacity more than double that of the concentric engine means and pump means arrangement of my aforementioned Patent No. 2,625,109, which is an important feature of the present invention. More particularly, the present end-to-end arrangement achieves a much higher capacity because of the fact that larger engine and pump pistons can be used as compared to the concentric arrangement mentioned. Also, larger operating-fluid andproduction-fluid passages are possible, such larger passages increasing the capacity of the pump 86 by reducing the resistances to flow of the operating and production fluids so that the rotor 300 can rotate at a much higher speed. In this connection, it will be noted that the operating-fluid intake and exhaust passages 372 and 192 are quite large, each having a crosssectional area approaching that of the engine cylinders 13 Similarly, the production fluid inlet and outlet pasthe single acting pumping devices of my aforementioned prior patent. Consequently, pressure pulsations are reduced by a factor of two.

Still another advantage of the present construction is that since the engine means and pump means of the pumping devices 314 are axially spaced, the cam means 332 for controlling the motions of the pumping devices, and for converting the reciprocatory motion into rotary motion of the rotor 300 can be located between the engine means and the pump means, thereby providing a compact construction.

Hydraulic balancing of rotor 300 M It will be noted that the operating fluid under pressure in the rotor chamber 268 acts on the lower end of the engine rotor sect-ion 302 to bias the engine end wall 310 of the engine rotor section into engagement with the engine end Wall 270 of the rotor chamber. Similarly, the operating fluid under pressure in the rotor chamber 268 acts on the upper end of the intermediate rotor section 306 to bias the pump end wall 312 of the pump rotor section V 304 into engagement with the pump end wall 272 of the rotor chamber 268. Such pressure induced engagement between the engine end walls 270 and 310 prevents leakage between the operating fluid intake and exhaust 168 and 190. Similarly, the resulting pressure induced engagement between the pump end walls 272 and 312 prevents leakage between the production fluid inlet and outlet 214 and 240. To prevent excessive engagement pressures between the engine'end walls 270 and 310 and between the pump end Walls 272 and 312, the engine and pump rotor sections 302 and 304 are partially balanced hydraulically, as will now be described. 7

As shown in FIG. 5, the interface between the engine end walls 270 and 310 is provided therein with an annular recess 384 surrounding the spindle portion 288. As shown in FIG. 10, a radial passage 386 extends from the annular clearance 354 through a radial passage 390, FIG. 15.

Consequently, the operating fluid pressure in the annular recess 388 reduces the engagement pressure between the pump end walls 272 and 312. 7

As will be apparent, the engagement pressures between the engine end walls 270 and 310 and between the pump end walls 272 and 312 can be varied byvarying the crosssectional areas of the annular recesses 384 and 388.

Flushing and lubricating with clean operating fluid An important feature of the invention is that all of the relatively movable components of the pump 86 are lubricated with clean operating fluid. More particularly an important feature is that clean operating fluid under pressure is conducted into the interfaces between all relatively movable components of the pump 86 which are exposed to the production fluid being pumped. With this construc tion, the clean operating fluid constantly leaks through such interfaces at slow rates to lubricate the relatively V movable surfaces and to preclude their contamination by the possibly-dirty production fluid, thereby minimizing wear.

Considering the foregoing in more detail, it will be apparent that the engine end walls 270 and 310 of the rotor chamber 268 and the rotor 300 are exposed only to the clean operating fluid. Similarly, the engine pistons and engine cylinders 316 and 318 are exposed only to the clean operating fluid, the same being true of the spindle portion 288 on which the engine rotor section 302 is rotatably mounted. In this connection, it will be noted that the engine rotor section 302 is provided with a wide, internal annular channel 392 which receives clean operating fluid for the purpose of lubricating the engine rotor section and the spindle portion 288.

Similarly, the cylindrical cam portion 292, the trape- Zoidal portions 324 of the engine pistons 316, the roller cam followers 336, and the roller-cam-follower spindles 338 are all exposed only to the clean operating fluid in the rotor chamber 268.

The interface between the intermediate rotor section 306 and the intermediate-diameter spindle portion 308 is lubricated by leakage of clean operating fluid through such interface from the interior of the rotor chamber 268 into the annular recess 364 containing production fluid at the considerably lower production-fluid inlet pressure. The interfaces between the pump piston rods 328 and their bores 330 are flushed and lubricated by leakage of clean operating fluid from the interior of the rotor chamber 268 through such interfaces into the upper ends of the pump cylinders 322, again because of the pressure differential between the pressure of the clean operating fluid and the production-fluid inlet pressure.

High-pressure clean operating fluid can also leak from the interior of the rotor chamber 268 along the rollercam-follower spindles 338 into axial passages 394 in the pump piston rods 328. The axial passages 394 terminate at their lower ends in radial ports 396 in the pump pistons 320. Consequently, the interfaces between the pump pistons 320 and the pump cylinders 322 are constantly flushed and lubricated with clean operating fluid.

The pump end walls 272 and 312 of the rotor chamber 268 and the rotor 300 are also flushed and lubricated with clean operating fluid. In this case, the source of the clean operating fluid is the annular recess 388 communicating with the annular clearance 354 around the pump rotor section 304 through the pass-age 390. As will be apparent, any leakage between the pump end walls 272 and 312 is always from the recess 388 toward the lower-pressure ports 376 and 378 and toward the lower ends of the pump cylinders 322. Also, clean operating fluid can leak radially inwardly between the pump end walls 272 and 312 from the external annular clearance 354 itself. Thus, the pump end walls 272 and 312 are constantly flushed and lubricated with clean operating fluid.

Clean operating fluid from the annular recess 388 can also leak upwardly through the interface between the spindle portion 290 and the pump rotor section 304. The latter is provided with a wide, internal annular channel 398 to receive clean-operating fluid leakage for lubrication purposes, such leakage progressing upwardly along the spindle portion 290 into the annular recess 364 containing production fluid at the production-fluid inlet pressure.

Thus, all relatively movable components are lubricated with clean operating fluid, and clean operating fluid leaks slowly between all relatively movable components which are exposed to production fluid so as to preclude the entry of production fluid between such components. The end result is that wear of the pump 86 is minimized, which is an important feature.

While the pump 86 has been shown in the drawings and described in this specification as incorporated in an articulated assembly of pumps, the pump 86 has adequate capacity to be used as a single pump. In this case the pump 86 may be adapted to either an open or a closed system. A sealing collar and packer nose assembly of the type shown in my Patents Nos. 2,568,320 and 2,589,670 may be used.

I have found that this unit is capable of operating at 18 high speed which produces a high capacity pump. The capacity is approximately as given in the following table:

, Rotor Speed, Capacity, Pump Size r.p.m. b./d.

and substitutions can be incorporated in such embodiments without departing from the spirit of the invention as defined by the claims which follow.

I claim:

1. A fluid operated well pumping apparatus hydraulically movable through a tubing system, including any bends therein, between an operating position in a well and a control station whereat said pumping apparatus can be inserted into or removed from the tubing system, said pumping apparatus being articulated and comprising at least two elongate units and means articulately interconnecting same in end-to-end relation, and said pumping apparatus including fluid operated engine means and pump means connected to and operable by said engine means, said engine means and pump means including housing means having movable, interconnected engine and pump elements therein.

2. A fluid operated well pumping apparatus hydraulie-ally movable through a tubing system, including any bends therein, between an operating position in a Well and a control station whereat said pumping apparatus can be inserted into or removed from the tubing system, said pumping apparatus being articulated and comprising at least two elongate units and means articulately interconnecting same in end-to-end relation, said pumping apparatus including fluid operated engine means and pump means connected to and operable by said engine means, said engine means and pump means including housing'means having movable, interconnected engine and pump elements therein, and said pumping apparatus including packer means engageable with the interior of the tubing system for providing a substantially fluid tight seal between said pumping apparatus and the tubing system irrespective of the direction of hydraulically induced movement of said pumping apparatus through the tubing system.

3. A fluid operated well pumping apparatus hydraulically movable through a tubing system, including any bends therein, between an operating position in a well and a control station whereat said pumping apparatus can be inserted into or removed from the tubing system, said pumping apparatus being articulated and comprising at least two elongate units and means articulately interconnecting same in end-to-end relation, one of said units including fluid operated engine means and pump means connected to and operable by said engine means, said engine means and pump means including housing means having movable, interconnected engine and pump elemets therein, and another of said units including packer means engageable with the interior of the tubing system for providing a substantially fluid tight seal between said pumping apparatus and the tubing system irrespective of the direction of hydraulically induced movement of said pumping apparatus through the tubing system.

4. In a fluid operated well pumping apparatus having upper and lower ends and hydraulically movable through a tubing system, including any bends therein, between an operating position in a Well and a control station whereat said pumping apparatus can be inserted into or removed from the tubing system, the combination of:

(a) at least two elongate units;

(b) means articulately interconnecting said units in end-to-end relation;

(0) the uppermost of said units including a packer mandrel carrying oppositely facing packer cups engageable with the interior of the tubing system;

((1) another of said units comprising fluid operated engine means and pump means connected to and operable by said engine means; and

(e) said engine means and pump means including hous ing means having movable, interconnected engine and pump elements therein.

5. In a fluid operated well pumping apparatus having upper and lower ends and hydraulically movable through a tubing system, including any bends therein, between an operating position in a well and a control station whereat said pumping apparatus can be inserted into or removed from the tubing system, the combination of:

(a) at least two elongate units;

(b) means articulately interconnecting said units in end-to-end relation;

(0) the uppermost of said units including a packer mandrel carrying oppositely facing packer cups engageable with the interior of the tubing system; and

((1) another of said units including a rotor mounted for rotation about an upright rotor axis and including circumferentially spaced, fluid operated, pumping devices carried by said rotor and reciprocable relative thereto along axes paralleling said rotor axis, each of said pumping devices including fluid operated engine means and pump means axially spaced from and connected to and operable by said engine means.

6. In a fluid operated well pumping apparatus having upper and lower ends and hydraulically movable through a tubing system, including any bends therein, between an operating position in a well and a control station whereat said pumping apparatus can be inserted into or removed from the tubing system, the combination of:

(a) an uppermost, at least two intermediate, and a lowermost elongate unit;

(b) means articulately interconnecting said units in endto-end relation;

(c) said uppermost unit including a packer mandrel carrying oppositely facing packer cups engageable with the interior of the tubing system;

(d) each of said intermediate units including a rotor mounted for rotation about an upright rotor axis and including circumferentially spaced, fluid operated, pumping devices carried by said rotor and reciprocable relative thereto along axes paralleling said rotor axis, each of said pumping devices including fluid operated engine means and pump means axially spaced from and connected to and operable by said engine means; and

(e) said lowermost unit including fluid operated booster pump means for delivering the fluid to be pumped to said intermediate units under pressure and in parallel.

7. In a rotary fluid operated pump, the combination of:

(a) a housing;

(b) a rotor mounted in said housing for rotation about a rotor axis;

(c). circumferentially spaced, fluid operated, differential double acting pumping devices carried by said rotor and reciprocable relative thereto along axes paralleling said rotor axis; and

(d) 'each of said pumping devices including fluid operated engine means and pump means axially spaced from and connected to and operable by said engine means.

8. In a rotary fluid operated pump, the combination of:

(a) a housing;

(b) a rotor mounted in said housing for rotation about a rotor axis;

(c) circumferentially spaced, fluid operated, dilferential double acting, pumping devices carried by said rotor and reciprocable relative thereto along axes paralleling said rotor axis;

(d) each of said pumping devices including fluid operated engine means and pump means connected to and operable by said engine means; and

(e) cylindrical cam means coaxial with said rotor and responsive to reciprocation of said pumping devices for rotating said rotor.

9. In a rotary fluid operated pump, the combination of:

(a) a housing having an intake and an exhaust for operating fluid and an inlet and an outlet for fluid being pumped;

(b) a rotor mounted in said housing for rotation about a rotor axis;

(c) circumferentially spaced, fluid operated, differential double acting pumping devices carried by said rotor and respectively including plunger means re-' ciprocable relative to said rotor along axes paralleling said rotor axis;

((1) each of said pumping devices comprising fluid operated engine means and pump means axially spaced from and connected to and operable by said engine means;

(e) cam means responsive to reciprocatory movement of said plunger means for rotating said rotor about said rotor axis;

(f) engine valve means responsive to rotation of said rotor for sequentially connecting said engine means to said intake and said exhaust alternately;'and

(g) pump valve means responsive to rotation of said rotor for sequentially connecting said pump means to said inlet and said outlet alternately.

10. In a rotary fluid operated pump, the combination of:

(a) a housing having an intake and an exhaust for operating fluid and an inlet and an outlet for fluid being pumped;

(b) a rotor mounted in said housing for rotation about a rotor axis;

(c) circumferentially spaced, fluid operated, pumping devices carried by said rotor and respectively including plunger means reciprocable relative to said rotor along axes paralleling said rotor axis;

(d) each of said pumping devices comprising fluid operated engine means and pump means connected to and operable by said engine means;

(e) double acting cam means coaxial with said rotor and engaging and responsive to reciprocatory movement of said plunger means for rotating said rotor about said rotor axis;

(f) engine valve means responsive to rotation of said rotor for sequentially connecting said engine means to said intake and said exhaust alternately at the ends of the respective strokes of said plunger means; and

(g) pump valve means responsive to rotation of said rotor for sequentially connecting said pump means to said inlet and said outlet alternately at the ends of the respective strokes of said plunger means; and

(h) said cam means including at least two dwell means for causing said plunger means to dwell at the ends of the respective strokes thereof.

11. A rotary fluid operated pump according to clai 10 wherein said cam means includes accelerating and decelerating means adjacent and on opposite sides of said dwell means for gradually accelerating and decelerating said plunger means at the beginnings and ends of the respective strokes thereof.

12. A rotary fluid operated pump according to claim 11 wherein said cam means include means intermediate. said accelerating and decelerating means for moving said.

plunger means at uniform speeds during major portions of the respective strokes thereof.

13. In a rotary fluid operated pump, the combination (a) a housing provided therein with a rotor chamber having axially spaced engine and pump end walls;

(b) said housing having an intake and an exhaust for operating fluid and an inlet and an outlet for fluid being pumped;

(c) a rotor mounted in said rotor chamber for rotation about a rotor axis and having axially spaced engine and pump end walls respectively engaging said engine and pump end walls of said rotor cham- 'ber;

(d) said rotor being provided with circumferentially spaced engine and pump cylinder means having axes paralleling said rotor axis;

(e) engine and pump plunger means respectively reciprocable axially of said cylinder means;

(f) cam means responsive to reciprocatory movement of said plunger means for rotating said rotor about said rotor axis;

g) engine valve means embodied in said engine end walls of said rotor chamber and said rotor, and responsive to rotation of said rotor, for sequentially connecting said cylinder means to said intake and said exhaust alternately;

(h) pump valve means embodied in said pump end walls of said rotor chamber and said rotor, and responsive to rotation of said rotor, for sequentially connecting said cylinder means to said inlet and said outlet alternately; and

(i) passage means communicating with said intake for conducting operating fluid under pressure into the interface between said engine end walls and the interface between said pump end walls.

14. In a rotary fluid operated pump, the combination (a) a housing provided therein with a rotor chamber having axially spaced engine and pump end walls;

(b) said housing having an intake and an exhaust for operating fluid and an inlet and an outlet for fluid being pumped;

(c) a rotor mounted in said rotor chamber for rotation about a rotor axis and having axially spaced engine and pump end Walls respectively engaging said engine and pump end walls of said rotor chamber;

(d) said rotor being provided with circum-ferentially spaced cylinder means having axes paralleling sai d rotor axis;

(e) each of said cylinder means including axially spaced engine and pump cylinders respectively [formed in said engine and pump end walls of said rotor;

(f) plunger means respectively reciprocable axially of said cylinder means;

(g) each of said plunger means including axially spaced, interconnected engine and pump pistons respectively reciprocable axially of said engine and pump cylinders of the corresponding one of said cylinder means;

(h) cam means responsive to reciprocatory movement of said plunger means for rotating said rotor about said rotor axis;

(i) engine valve means embodied in said engine end Walls of said rotor chamber and said rotor, and responsive to rotation of said rotor, for sequentially connecting said engine cylinders to said intake and said exhaust alternately;

(j) pump valve means embodied in said pump end walls of said rotor chamber and said rotor, and responsive to rotation of said rotor, for sequentially connecting said pump cylinders to said inlet and said outlet alternately; and

(k) passage means communicating with said intake for conducting operating fluid under pressure into 15. In a rotary fluid operated pump, the combination (a) a housing provided therein with a rotor chamber having axially spaced engine and pump end walls;

(b) said housing having an intake and an exhaust for operating fluid and an inlet and an outlet for fluid being pumped;

(c) a rotor mounted in said rotor chamber for rotation about a rotor axis and having axially spaced engine and pump end walls respectively engaging said engine and pump end walls of said rotor chamber;

((1) said rotor being provided with circumferentially spaced cylinder means having axes paralleling said rotor axis; t

(e) each of said cylinder means including axially spaced engine and pump cylinders respectively formed in said engine and pump end walls of said rotor;

(f) plunger means respectively reciprocable axially of said cylinder means;

(g) each of said plunger means including axially spaced, interconnected engine and pump pistons respectively reciprocable axially of said engine and pump cylinders of the corresponding one of said cylinder means;

(h) cam means responsive to reciprocatory movement of said plunger means for rotating said rotor about said rotor axis;

(i) engine valve means embodied in said engine end walls of said rotor chamber and said rotor, and responsive to rotation of said rotor, for sequentially connecting said engine cylinders to said intake and said exhaust alternately;

(j) pump valve means embodied in said pump end walls of said rotor chamber and said rotor, and responsive to rotation of said rotor, for sequentially connecting said pump cylinders to said inlet and said outlet alternately;

(k) passage means communicating with said intake for conducting operating fluid under pressure into the interface between said engine end walls and the interface between said pump end walls; and

(l) passage means communicating with said intake for conducting operating fluid under pressure into the interfaces between said pump cylinders and pump pistons.

16. In a rotary fluid operated pump, the combination (a) a housing having an intake and an exhaust for operating fluid and an inlet and an outlet for fluid being pumped;

(b) a rotor mounted in said housing for rotation about a rotor axis and provided with circumferentially spaced cylinder means having axes paralleling said rotor axis;

(c) each of said cylinder means including axially spaced engine and pump cylinders;

(d) plunger means respectively reciprocable axially of said cylinder means;

(e) each of said plunger means including axially spaced, interconnected engine and pump pistons respectively reciprocable axially of said engine and pump cylinders of the corresponding one of said cylinder means;

(f) cam means responsive to reciprocatory movement of said plunger means for rotating said rotor about said rotor axis;

(g) engine valve means responsive to rotation of said rotor for sequentially connecting said engine cylinders to said intake and said exhaust alternately;

(h) pump valve means responsive to rotation of said rotor for sequentially connecting said pump cylinders to said inlet and said outlet alternately; and

(i) passage means communicating with said intake 23 for conducting operating fluid under pressure into the interfaces between said pump cylinders and pump pistons.

17. In a rotary fluid operated pump, the combination (a) a housing having an intake and an exhaust for operating fluid and an inlet and an outlet for fluid being pumped;

(b) a rotor;

(c) means mounting said rotor in said housing for rotation about a rotor axis;

((1) said rotor being provided with circumferentially spaced engine and pump cylinder means having axes paralleling said rotor axis;

(e) engine and pump plunger means respectively reciprocable axially of said cylinder means;

(f) cam means responsive to reciprocatory movement of said plunger means for rotating said rotor about said rotor axis;

(g) engine valve means responsive to rotation of said rotor for sequentially connecting said cylinder means to said intake and said exhaust alternately;

(h) pump valve means responsive to rotation of said rotor for sequentially connecting said cylinder means to said inlet and said outlet alternately; and

(i) passage means communicating with said intake for conducting operating fluid under pressure into the interfaces between all relatively movable surfaces of said housing, rotor mounting means, rotor, cylinder means, plunger means and pump valve means which are exposed to the fluid being pumped.

18. In a rotary fluid operated pump, the combination (a) a housing having an intake and an exhaust for operating fluid and an inlet and an outlet for fluid being pumped;

(b) a rotor mounted in said housing for rotation about a rotor axis and provided with circumferentially spaced cylinder means having axes paralleling said rotor axis;

(c) each of said cylinder means including axially spaced engine and pump cylinders;

(d) plunger means respectively reciprocable axially of said cylinder means;

(e) each of said plunger means including axially spaced, interconnected engine and pump pistons respectively reciprocable axially of said engine and pump cylinders of the corresponding one of said cylinder means;

(f) each of said engine pistons having oppositely facing,

major and minor engine areas;

(g) each of said pump pistons having oppositely facing, major and minor pump areas;

(h) said major engine and pump areas facing opposite- (i) cam means responsive to reciprocatory movement of said plunger means for rotating said rotor about said rotor axis;

(j) engine valve means responsive to rotation of said rotor for sequentially connecting said major engine areas to said intake and said exhaust alternately; and

(k) pump valve means responsive to rotation of said rotor for sequentially connecting said major pump areas to said inlet and said outlet alternately.

19. In a rotary fluid operated pump, the combination (a) a housing having an intake and an exhaust for operating fluid and an inlet and an outlet for fluid being pumped;

(b) a rotor mounted in said housing for rotation about a rotor axis and provided with circumferentially spaced cylinder means having axes paralleling said rotor axis;

(c) each of said cylinder means including axially spaced engine and pump cylinders;

(d) plunger means respectively reciprocable axially of said cylinder means;

(e) each of said plunger means including axially spaced, interconnected engine and pump pistons respectively reciprocable axially of said engine and pump cylinders of the corresponding one of said cylinder means; V

(f) each of said engine pistons having oppositely facing, major and minor engine areas;

(g) each of said pump pistons having oppositely facing, major and minor pump areas;

(b) said major engine and pump areas facing oppositely;

(i) cam means responsive to reciprocatory movement of said plunger means for rotating said rotor about said rotor axis;

(j) engine valve means responsive to rotation of said rotor for sequentially connecting said major engine areas to said intake and said exhaust alternately;

(k) pump valve means responsive to rotation of said rotor for sequentially connecting saidmajor pump areas to said inlet and said outlet alternately; and

(l) passage means constantly connecting said minor engine areas to said intake.

20. In a rotary fluid operated pump, the combination (a) housing having an intake and an exhaust for operating fluid and an inlet and an outlet for fluid being pumped;

(b) a rotor mounted in said housing for rotation about a rotor axis and provided with circumferentially spaced cylinder means having axes paralleling said rotor axis;

(c) each of said cylinder means including axially spaced engine and pump cylinders; I

(d) plunger means respectively reciprocable axially of said cylinder means;

(e) each of said plunger means including axially spaced, interconnected engine and pump pistons respectively reciprocable axially of said engine and pump cylinders of the corresponding one of said cylinder means;

(f) each of said engine pistons having oppositely facing, major and minor engine areas;

(g) each of said pump pistons having oppositely facing, major and minor pump areas;

(h) said major engine and pump areas facing oppositely;

(i) cam means responsive to reciprocatory movement of said plunger means for rotating said rotor about said rotor axis;

(j) engine valve means responsive to rotation of said rotor for sequentially connecting said major engine areas to said intake and said exhaust alternately;

(k) pump valve means responsive to rotation of said rotor for sequentially connecting said major pump areas to said inlet and said outlet alternately; and

(l) passage means constantly connecting said minor pump areas to said inlet.

21. In a rotary fluid operated pump, the combination (a) a housing having an intake and an exhaust for operating fluid and an inlet and an outlet for fluid being pumped;

(b) a rotor mounted in said housing for rotation about a rotor axis and provided with circumferentially spaced cylinder means having axes paralleling said rotor axis;

(0) each of said cylinder means including axially spaced engine and pump cylinders;

(d) plunger means respectively reciprocable axially of said cylinder means;

(e) each of said plunger means including axially spaced, interconnected engine and pump pistons respectively reciprocable axially of said engine and pump cylinders of the corresponding one of said cylinder means;

(f) each of said engine pistons having oppositely facing, major and minor engine areas;

(g) each of said pump pistons having oppositely facing, major and minor pump areas;

(h) said major engine and pump areas facing oppositely;

(i) cam means responsive to reciprocatory movement of said plunger means for rotating said rotor about 10 said rotor axis;

(j) engine valve means responsive to rotation of said rotor for sequentially connecting said major engine areas to said intake and said exhaust alternately;

(k) pump valve means responsive to rotation of said rotor for sequentially connecting said major pump areas to said inlet and said outlet alternately;

(l) passage means constantly connecting said minor engine areas to said intake; and

(m) passage means constantly connecting said minor pump areas to said inlet.

References Cited UNITED STATES PATENTS 1,836,872 12/1931 Ricker 103-52 2,674,951 4/1954 Zaba 10352 2,679,139 5/1954 Posson.

2,862,449 12/1958 Wyland 103-49 2,935,952 5/1960 Rose 10349 X 3,046,898 7/1962 Badenoch et al 10349 15 ROBERT M. WALKER, Primary Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No 3,322 ,069 May 30 1967 Clarence J. Coberly It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 2, lines 26 and 27, strike out "pistons respectively reciprocable axially of the engine and pump";

column 9, line 45, for "ats" read at column 10, lines 17 and 18, for "communicatse" read communicates column 12, line 33, for "wal" read wall column 13, line 42, after "means," insert to be described hereinafter, sequentially connect the column 14, line 29, for "expoesd" read exposed column 15, line 43, for "arcualte" read arcuate column 18, lines 62 and 63, for "elemets" read elements column 19, line 64, after "acting" insert a comma; column 20, line 18, after "acting" insert a comma; line 56, strike out "and"; column 24, line 27, before "housing" insert a Signed and sealed this 9th day of January 1968.

(SEAL) Attest:

EDWARD M.FLETCHER,JR. EDWARD J. BRENNER Attesting- Officer Commissioner of Patents 

1. A FLUID OPERATED WELL PUMPING APPARATUS HYDRAULICALLY MOVABLE THROUGH A TUBING SYSTEM, INCLUDING ANY BENDS THEREIN, BETWEEN AN OPERATING POSITION IN A WELL AND A CONTROL STATION WHEREAT SAID PUMPING APPARATUS CAN BE INSERTED INTO OR REMOVED FROM THE TUBING SYSTEM, SAID PUMPING APPARATUS BEING ARTICULATED AND COMPRISING AT LEAST TWO ELONGATE UNITS AND MEANS ARTICULATELY INTERCONNECTING SAME IN END-TO-END RELATION, AND SAID PUMPING APPARATUS INCLUDING FLUID OPERATED ENGINE MEANS AND 